Aluminum-glazed black powder.



it falllhlli l lf lill ldlifllil FIN SPARBQE, OF VJILMINGTON, DELAWARE,ASSIGI-IOR- TO E. I. no FONT DE NEMOURS POWDER CGMPAINY, OF WILMINGTON,DELAWAIi-E, A CORPORATION 033 NEW JERSEY.

ALUMINUM-GLAZED BLACK POVIDER.

No Erawi T 0 all 207:0120 '22 concern:

Be it known at I, FIN Seamus, lVilmington, in the county of New Castleand in the State of Delaware, have invented a certain'new and usefulImprovement in Aluminuin-Glazed Black Powder, and do hereby declare thatthe following is a full, clear, and exact description thereof.

My intention relatcs'to an improvement in black gunpowder but hasspecial refer once to the coating of granulated black gunpowder, such,for example, as that used in blasting operations.

My invention relates especially, however, to providing a. coating forsuch powder.

Hitherto gunpowder for blasting purposes or for firearms has beenmanufactured with a coating of graphite, the same having been applied asthe last step in the roanulao ture thereof. Such coating of graphite hasbeen called glazing, inasmuch as its presence provides the powder with asmoother surface and renders the surface thereof glossy.

Textbooks, referring to glazing by the application of a coating ofgraphite, state that such coating reduces the hygroscopicity or thepowder and that it causes the powder to run more easily in the loadingmachines and that it also assists in obtaining uniform ballistic resultsin firearms. It has been dour onstrated, however that the use of acoating of graphite renders the powder less hygroscopic to only anegligible degree and, furthermore, that the ease of running in theloading machines and bore holes not entirely dependent upon theapplication. oi a coating of graphite but that this result may a so beohtained t an extent suilicient for mos purposes by a ruhbin of thegrains or by tumbling the in a barrel. has

n (:01. cited a co a r. c- .4-

lcci s tae strength or ing gr too powder.

lne 0 J -ention is to overcome previous ms inventi on comp-i coatingupon black 1 of pulverized metallic sr Fit-g aluminum. This l= "I a cotin and in general Specification of Letters Patent.

application filed deptember 20,1913. Serial No. 790,846.

Patented Nov. 10 191 ll,

parent from the fact that the coating material is a good conductor ofheat and from the fact that aluminum is a component frequently used in"producing explosives. Graphite, on the other hand is a non-activesubstance it burns with considerable dill.- culty compared with. theother ingredients present in such powder and as it conse qucntly lowersthe rate of ignition. As I have previously pointed out aluminum has beenpreviously used as an ingredient of cX- plosives. to the use ofaluminiun as a general ingredient of powder of the kind referred to. This will be evident from the small percentage which I ordinarily use inproducing hlacl; powder in accordzmcc with my invention. Ordinarily lhepercentage of aluminum which I use is than (X53? and the pcrgpenljage asa rule would he less than 0.971., iii view of the fact that only aportion of the pulverized aluminum added to the powder would adhere tothe powder.

My invention directed particularly to the elimination of. theobjectionable coating agent which has been previously used, graphite,and to providing a coating which does not retard ignition but which infact hastens the speed of ignition. The coating which I use is moreadvantageous than graphite for the further reason that it may he appliedin a fraction of the time required for the application of graphite, andinasmuch a smaller quantity of my coating may he used than in the caseof graphite.

i'l hile my invention s capahlh of being carried out; n many (1i outways, tor the purposes of illustration I shall set forth an example ofthe way in which it may be accou'iplishcd. For example, i. may use as acoating pulverized alun'iinuin. The aluini 'niun inlay he applied to thepowder in e1rthe same manner a raphite now change the character of thepowder. The

char e in the barrel is then revolved for a suite 1e time as, forexample, from fifteen to thirty minutes. I have in some instances,

however, been able to apply the aluminum in a shorter time, as forexample, ten min utes, but it is conceivable that with different methodsthe time mi ht be longer even than thirty minutes. During the coatingprocess the materials may-or may not be heated as found desirable, asfor example according to the humidity of the atmosphere. It may also befound desirable to run the grain directly from the mill into a revolvingbarrel for a period of time as, for example, a few hours, during whichtime the powder may if desired be heated, either by warm air being blowninto it or by the friction generated by the movement of the powder inthe barrel. Thereupon, after the owder has become smooth and has beenried in the barrel, and preferablyafter the dust has been. separatedtherefrom, the aluminum may be added and applied as indicated above.

While I have described my invention abovein detail I wish it to beunderstood that man changes may be made therein without eparting fromthe spirit of my invention;

I claim:-

to granulated uncoated black powder a coating of a metallic substancecontaining alu minum.

2. The process which comprises applying,

to granulated uncoated black powder a coat ing of aluminum.

3. An explosive comprising granulated black powder having a coating of ametallic substance containing aluminum located contiguous to the bodiesof black powder in the grains.

4:. An explosive comprising granulated 4 3, 1. The process whichcomprises applying

